Procedure:Working with a partner:
1. Using a hand lens or a dissecting microscope, examine a portion
of the plant to be used
in this experiment.
Describe the characteristics of a healthy plant.

2. Label 6 test tubes as follows:

2 Test tubes - 1 & 2

2 Test tubes - 3 & 4

2 Test tubes - 5 & 6

3. Fill each test tube approximately half full with the fresh or aquarium
water sample.
4. Add a sprig of the plant to each test tube.
5. Place the test tubes in a rack or a beaker and place each group
of two in the appropriate
location.

Test tubes 1 & 2-Refrigerator or ice bath

Test tubes 3 & 4-Incubator or light source

Test tubes 5 & 6-Room temperature

6. Place a thermometer in each location as close as possible to the test
tubes.
7. Take a temperature reading from each location after approximately
10 minutes. This
will allow time for the temperature to stabilize.
8. Record the temperature readings in the data table under Day 1.
9. Based on your knowledge of aquatic ecosystems and temperature, hypothesize
how the
cultures will change over a 24 hour period.

Hypothesis:

10. Record each of the temperature readings and observations on the
data table for the next four
days.

Data Table:

After the observations are complete, answer the following questions

Conclusions:1. Based on your observations, what would be the optimal temperature
for the growth and
development of aquatic plants?

2. Based on your observations, what would happen to plants in an aquatic
ecosystem if the
temperature increased or decreased?

3. How would this effect the aquatic ecosystem as a whole? (Consider
other organisms
such as macroinvertebrates and fish)

4. Research the effects of thermal pollution on aquatic plants. Write
a short paragraph
explaining what thermal pollution is and how it effects an aquatic
ecosystem. In addition,
include how this problem can be alleviated.